U.S. Pat. Nos. 3,050,228, 3,412,920, and Re. 26,557 describe shipping containers having a reinforcing crush resistant panel extending across the container. These basically include a cubical outer container of generally conventional corregated box construction with separately formed insert panels. This type of construction often wasted material in that certain areas were double walled to prevent the rigidifying panel from shifting in the carton. Also, the rigidifying panel often was not securely anchored to the main carton.
Other types of cartons with crush resistant rigidifying panels were used for eggs, etc. and are described in U.S. Pat. Nos. 2,597,846 and 4,046,307. These have complicated constructions which required three or more separate parts to be assembled into the rigidified carton.
Another problem with shipper containers for merchandise such as bottle liquids, was that they required a series of cardboard dividers as shown in the U.S. Pat. No. 3,256,983 to prevent the bottles from abrading each other and breaking during handling. This patent describes a shipper case for beer bottles.
The problem of shipping bottled liquids is compounded in the medical field in that many of the bottled liquids, in glass or plastic, have critical sterile contents that are administered into a patient's vein or used during surgery. Thus, it is extremely critical that the shipper container be sturdy so as not to crack and possibly contaminate any of the bottles of medical liquid. The containers also must be very economical, as much of the recent shipment of medical liquids has been in disposable plastic containers that are not returned to the manufacturer. Thus, the shipper case is destroyed along with the used bottles at the hospital.